The Isuzu FTR uses front turn signal bulbs in 1157 and 1156 sizes, with rear turn signal bulbs in 1156 size. The replacement chart covers vehicle production years from 1988 to 2011 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1156 and 1157 bulbs are the two types specified across all model years of the Isuzu FTR's turn signal system, making them the dominant bulb types throughout the vehicle's production span covered in these specifications.
The 1157 is a dual-filament bulb operating at 12V with a 21W/5W output and a BAY15d bayonet base, conforming to ANSI standards recognized in both the US and Canada.
The 1156 is a single-filament bulb operating at 12V with a 21W output and a BA15s bayonet base, also conforming to ANSI standards recognized in both the US and Canada.
The BAY15d base of the 1157 and the BA15s base of the 1156 are physically distinct, as the BAY15d features offset locking pins to accommodate its dual-filament design, while the BA15s uses a single-pin alignment. These two bulbs are not interchangeable.
The front turn signal of the Isuzu FTR uses the dual-filament 1157 from 1996-2011, while the rear turn signal uses the single-filament 1156 across that same period, meaning the front and rear positions require different bulb types during those years.
For the 1988-1994 Heavy Duty trim, both the front and rear turn signals specify the 1156 single-filament bulb, making the front and rear positions compatible with the same bulb type during that period.
The 1995 Heavy Duty trim marks a transition year for the front turn signal, where the specification shifts from the 1156 to the 1157, while the rear turn signal retains the 1156.
The Tilt Cab trim, covering 2002-2011, consistently specifies the 1157 for the front turn signal and the 1156 for the rear, maintaining the same front-to-rear distinction seen in the preceding non-trim-designated years from 1996-2001.